textproduct: Quad Cities

KEY MESSAGES

- Scattered showers and isolated thunderstorms tonight, with likely the highest coverage (~40 percent) over eastern Iowa; a few marginally severe storms possible.

- During a windy Sunday, rain will spread north across the area during the afternoon with embedded thunderstorm potential into the evening; again a marginally severe storm or two possible.

- Warm and seasonably humid air mass Monday through Wednesday will support periods of rain and thunderstorms, with some likely being organized posing occasional severe threats.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 240 PM CDT Sat Apr 11 2026

A gradually decaying mesoscale convective vortex (MCV) in eastern Iowa this afternoon will continue some rain as it tracks northeast through late afternoon. Our 18Z sounding sampled minimal mid-level lapse rates, so any thunderstorm potential is mainly in far southeast Iowa and northeast Missouri through 7 P.M. Behind this MCV will be a brief period (2-4 hours) of suppression limiting any shower development in its wake.

Tonight...Satellite water vapor imagery and regional mid-level VWP data indicate multiple small short waves upstream back as far as the Central Plains that will traverse over at least the western CWA (eastern Iowa) tonight. A strengthening low-level jet over the region will support continued warm air advection aloft (WAA) and moisture transport that these subtle waves can interact with. Not surprisingly, CAMs show a plethora of solutions, but generally scattered convective coverage that ranges a little higher with northwest extent in the CWA. MUCAPEs are on the order of 200-500 J/kg and of a tall and skinny variety, with deep layer shear near 30 kt. That might mean mainly small hail with any persistent cores.

Sunday and Sunday night...As a 995 mb low pressure gradually deepens across the Northern Plains on Sunday, south-southwest winds will increase over the area and probably will do so early in the day (7-10 AM). Depending on the amount of solar insolation in the morning, which is low confidence as it could be cloudy with still some spotty convective activity, sporadic 40 mph wind gusts could result. During the afternoon within the residual moisture transport plume, a short wave is forecast to track northeast across the CWA, with some longitudinal spread in guidance. Either way, high PoPs remain in order especially mid- afternoon through evening. Ahead of this wave in the far eastern CWA (north central Illinois), some surface-based storms may be able to pop with forecast temperatures in the mid 70s at or slightly above the forecast convective temperatures. A strong storm or two cannot be ruled out with this. Otherwise, within the broader shield of rain there is some signal for embedded thunderstorms, probably of a 20-30 percent coverage type. Rainfall amounts Sunday afternoon just northwest of the short wave center will probably see over one half inch of rain with a 30 percent chance of exceeding one inch per latest NBM data.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 240 PM CDT Sat Apr 11 2026

A broader western CONUS trough on Monday will gradually move east-northeast and over the Midwest by Wednesday, potentially acquiring a negative tilt as it does so. With a surface front in the vicinity, likely oscillating some due to mesoscale effects, this presents an active pattern in the region.

Monday...Confidence is high in the surface warm front lifting north of the area by or during Monday morning. An elevated mixed layer (EML) is forecast to move over, and deterministic guidance generally is void of any short waves in that time. So those two together currently indicate much of if not the entire daytime could be quiet in our forecast area, and a warm and increasingly humid one with high temperatures 75 to 80 favored and dew points increasing into the mid 60s. Convective development is most favored ahead of the low which currently is in the southern Minnesota region later Monday. The right entrance region of the jet is forecast to move a little more north of east, while thickness diffluence would support organized convection potentially tracking a little more south of east and being more problematic for our area with a severe wind threat Monday night. So tough to say at this point yet. Also, some isolated low-level jet forced convective development may sprout over our area Monday night as well.

Tuesday and Wednesday...The first low pressure weakens while a second, stronger one deepens in the western to central Plains Tuesday. This type of setup is common with a slow-moving western CONUS upper trough. The surface boundary on most guidance is forecast to be slightly north to over the area and likely reacquiring warm frontal characteristic Tuesday P.M., although that may depend on any mesoscale convective influences that are simply too difficult to pinpoint at this distance. If no convective effects, temperatures should be able to top 80 areawide with 15-17C under a southwesterly low-level jet and a very warm starting point to the day (60s -- potential daily record warm lows for April 14). Obviously with a warm front in the area during mid-spring, that will be a time period to watch, including possible heavy rainfall Tuesday night. As that low approaches the area, possibly the best kinematics of the few days spread over the area Wednesday, although timing differences become much more evident in ensemble memberships and deterministic guidance at this point. All in all, this presents a 48 hour period or so from Monday night through Wednesday evening with some severe weather threat, with specific magnitudes and timing being more resolved as we draw closer.

Beyond...Pattern looks to stay active but possibly more progressive during the latter half of next week. With no significant cool air behind it, temperatures should remain above normal.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1245 PM CDT Sat Apr 11 2026

A small scale weather disturbance moving into eastern Iowa this afternoon has maintained a presence of rain with some embedded thunderstorms, namely along/south of the Iowa border. This should lift east-northeast, with additional shower development probable with this to the northeast. Overall the impacts from these would be some MVFR ceilings and possible temporary MVFR visibility.

The chance for scattered showers and isolated storms will continue tonight into Sunday morning, with low confidence on any one specific area or even timing of these. Have some PROB30s in the TAF for these and hopefully more confidence is obtained on yay/nay to showers or storms by the 00Z issuance. Of higher confidence tonight is a south-southwest low-level jet with 45+ kt flow as low as 1,500-2,000 ft, so continue to include LLWS that should persist a little after daybreak Sunday.

Surface southwesterly winds on Sunday morning through mid- afternoon will be stout as the pressure gradient tightens. It is low confidence, however, how high gusts will reach due to probable cloud cover. There is a 30-50 percent chance of reaching sporadic 35 kt gusts at this point.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.